1. Field of the Invention
The invention concerns an apparatus for decapitating fish, comprising a conveying device for advancing fish transverse to their longitudinal axis, which conveying device comprises a conveyor for receiving the rumps of the fish and provided with entrainers, and an auxiliary conveyor for receiving the heads of the fish guided parallel to the conveyor and equipped with holding elements adjustable in their position with respect to the path of the entrainers, the apparatus further comprising a severing device for performing a wedge-shaped cut by means of knives, this severing device being arranged between the conveyor and the auxiliary conveyor and having guide rails, which are arranged to be displaced by the fish synchronously in an opposing manner and positioned essentially in the plane of the knives.
2. Description of Prior Art
An apparatus of this type can be taken from DE-OS No. 27 35 302, in which apparatus fish positioned on an entraining conveyor lying on their sides and belly first are supplied to a severing aggregate for performing a wedge-shaped cut. In this apparatus a pin or a pair of pins penetrating into the eye-hole, respectively, locate the fish in the direction of their longitudinal axes, whereby a pre-alignment of the fish is effected. The pins are adjustable in their position with respect to the cutting planes of the severing aggregate. A coupling mechanism is provided for the adjustment in dependence on the thickness of the respective fish head, which mechanism effects a transmission of the measuring position of two measuring arms to the pins, which arms are synchronised in an opposing manner and detect the head thickness of the fish. Thereby it is to be achieved that each fish is positioned according to its respective size such that each decapitating cut can be performed with a yield of flesh as high as possible. This works essentially without any adjustment as long as the isthmus connecting the head of the fish with its rump on the belly side has been severed by a preceding processing step, i.e. if the gill cavity is opened ventrally. If, however, fish are processed which have not been prepared in this manner before, the coupling mechanism must be adjusted correspondingly. However, it has been found that such an adjustment only enables the processing of a relatively small range of sizes with the desired economy.